This invention relates to vertical lifting and placing devices and more particularly relates to vertical lifting and placing devices which can be manuevered by a single person and thereafter locked in position to enable manipulation of the load being lifted.
There are many designs available for vertical lifting equipment, both general and special purpose. Much of this equipment is not readily manueverable with a load in place, is not useful adjacent vertical walls or in corner locations, provides only a single vertical lifting mechanism or requires several persons to assemble and use the equipment. Further, many devices require the operator to use both hands to lift or manuever the device, whereby the load being lifted is either unattended or additional people are required to complete the operation.
In the construction industry, by way of example, it is often required that heavy objects be lifted to a desired vertical position and held in that position while the objects are attached to surrounding structure. Several workers may be required simply to hold an object while the object is secured in position. It is apparent that such workers are not effectively used. It is also difficult to manually hold objects in position for accurate locating relative to other objects.
One particular onerous job is the installation of cabinets. Not only must the cabinets be installed in a vertical position but also against a vertical wall or in a corner position so that access to the cabinets is limited. At least two persons may be required to raise a cabinet into position and one of the persons must then undertake to both hold and install the cabinet or three persons may be used to free one of the persons for only installation work.
In addition, many lifting devices are designed to place objects in only a vertical mode. If the center-of-gravity of the object being lifted is not centered with the lifting device, the lifting operation can become unstable and dangerous. Further, no manipulation is available to stably move an object both vertically and laterally for movement into a corner location, either a horizontal or a vertical corner. This is particularly true if the operation is attempted with only a single operator.
The disadvantages of the prior art are overcome by the present invention, however, and improved vertical lift apparatus are provided for a single operator to safely and accurately place an object in a vertical position for installation.